This season 7 opener was a moment of clarity for Barney and Robin. It forshadowed their eventual reuniting as a couple, but first Barney had to actually care about a woman and not use bad pickup scenarios, like pretending to be a prison escapee and wearing overgrown fingernails. Nora (Nazanin Boniadi), who called him back in this episode, helped him mature.

The episode also shows the day of Barney’s wedding, and we see Marshall ruin Ted’s friend Punchy’s wedding. But most importantly, Barney and Robin perform an epic dance to “Groove is in the Heart,” schooling everyone at the Cleveland wedding.

Lastly, this episode that has one of my favorite conversations from the show:

Robin Scherbatsky: “...You got chemistry, you only need one other thing.”

Brunch is supposed to a pleasant affair, but it’s not in this season 2 episode.

Ted thinks his dad cheated on his mom, Barney is mad at Ted’s dad for being a bad wingman, Lily and Marshall can’t handle not being together and Robin wants Ted’s mom to be honest about the fact that she and Ted’s father have separated.

It’s a mess of fighting told in different segments all leading up to a blowout after taking a nice group photo.

A lost phone number on Halloween leads to years of wearing the same “hanging chad” costume (referencing the 2000 election) and attending the same boring rooftop party.

This season 1 episode sounds like it could be a drag, but it’s an early episode that sets up a lot of character development.

Viewers see how Lilly and Marshall interact as a couple as they wearing matching costumes and share food. In contrast, viewers see Ted’s hopeful longing for “the one” and Robin’s inability to truly let someone into her life.

It’s too bad the season 7 episode The Slutty Pumpkin Returns (first aired Oct. 31, 2011) didn’t live up to its hype. Sorry, Katie Holmes, not even you could save that snoozefest of an episode.

By far the best episode of season 9, this episode gave viewers what they had wanted for years: the mother’s backstory.

Cristin Milioti did a fabulous job, and it was fun to see many of the clues viewers had seen throughout the show’s run from her character’s point of view.

1. Girls Vs. Suits (first aired Jan. 11, 2010)

The show’s 100th episode featured one hilarious song-and-dance number.

When Barney has to choose between his signature attire of suits and a girl, he dreams up his “Nothing Suits Me Like a Suit” fantasy, complete with a suit in the sky with angel wings and lyrics such as “Wingman I can wear/They're oh so debonair/The perfect way to snare/A girl with daddy issues.”